What does quintile mean?
A quintile is one of five equal parts of a whole, especially in the analysis of income, wealth, or population. For example, researchers may compare the earnings, health outcomes, or educational attainment of households in the lowest and highest income quintiles. More generally, the word can denote a group or arrangement of five. In astrology, a quintile is an aspect in which two planets are 72 degrees apart, representing one-fifth of the zodiacal circle. The word derives from Latin quintus, meaning “fifth,” and is related to quintet, quintuple, and other English words involving the number five. It is especially useful in social statistics, where it provides a simple way to describe ranked sections of a population without naming each section separately.
A fifth part, especially one of five equal divisions of a population, income distribution, or other whole.
"The report examines the consumption habits of the richest income quintile."
This is the most common modern use, especially in economics, demography, and social research.
A group or arrangement of five.
"The quintile of volunteers completed the final stage of the relay."
This sense is less frequent than the statistical meaning.
In astrology, an aspect between two planets separated by 72 degrees.
"The astrologer noted a quintile between the two chart points."
This is a specialized astrological term.
The plural is used when referring to the five ranked sections of a population or distribution.
"The study compares education levels across the five income quintiles."
A quintile is how demographers divide a population into five slices—from the lowest-income fifth to the highest-income fifth.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does quintile come from?
The English word comes from Latin quintus, meaning “fifth,” through the related Latin formation quintilis. In English, the term was established for the idea of a fifth part and later became familiar through statistical and economic usage. Its astrological sense reflects the same numerical idea: a quintile is one-fifth of a 360-degree circle, or 72 degrees.
Related word forms
How quintile is actually used
The statistical and economic senses are standard in British and American English. In astrology, the term is technical and usually refers to a specific geometric aspect.